1. Field of the Invention
The exemplary embodiment(s) of the present invention relates to a sensor system. More specifically, the exemplary embodiment(s) of the present invention relates to an optical sensor system.
2. Description of Related Art
In recent years, the LED technology has big progress in the brightness efficiency, and many applications for displays continuously appear. Also, the optical proximity sensor (OPS) apparatus is commonly used in wireless communications, bio-molecular sciences, environmental monitoring, and displays. The OPS apparatus is developed based on the light signal received by the photo-diode (PD) via the reflections of the measured object. The PD transfers the light signal to the electrical signal. By detecting the intensity of the electrical signal, the OPS apparatus can obtain the direction of movement of the measured object.
For example, a traditional OPS system, such as a quadrant photodiode system, may be used to determine whether an object is moved from one direction to the other direction above the display of an electronic device, and then the electronic device can determine the moving direction for position or motion sensing. However, in such a case, the quadrant photodiode system needs some sort of focusing lens or light projection system to project image onto the quadrant detectors of the quadrant photodiode system, and the quadrant photodiode cells in the quadrant photodiodes need to be located adjacent to each other. Because the optical focusing lens is needed, the light detection viewing angle would be dramatically reduced resulting in light brightness and color temperature sensing errors. Besides, packaging with integrated physical focusing lens on sensor will significantly increase the overall package thickness over 2 mm, thereby making the quadrant photodiode system difficult to be applied in mobile device applications. Moreover, continuous sampling at a very high speed for position or motion sensing is necessary in the quadrant photodiode system, therefore increasing power consumption. The phenomenon mentioned above is an unwanted drawback for all the users.
Thus, for the demand, designing an optical sensor system to increase the accuracy of detecting the position or motion of the object and to decrease the power consumption has become an urgent issue for the application in the market.